Is the anion below nonaromatic, antiaromatic, or aromatic? If it is aromatic, what is its n in Hückel's rule? If not, explain the aromaticity rule it breaks.

The anion is aromatic. Its n is 2.

The anion is aromatic. Its n is 5.

The anion is antiaromatic. It breaks the aromaticity rule because it does not have a (4n + 2) number of π electrons.

The anion is nonaromatic. It breaks the aromaticity rule because it is not planar.